The Reasearch Of Synthesis And Surface Complexation Of Copper Oxide And Basic Cupric Carbonate Nano Mineral

Copper is a kind of important industrial raw materials, widely used in all kinds of fields.People,s demand for copper mineral resources becomes more and more, but the coppermineral resources which can be used are very limited. In addition, copper resources in Chinais characterised by low grade, a lot of oxide copper mineral resources are not reasonablebyexploited and utilizated due to the high oxidation rate and the large quantity of complex fineparticles. Compared with copper sulfide, copper oxide and carbonate have high solubility,therefore, the flotation efficiency is much lower. In view of the current problems, how toimprove the selective flotation efficiency of copper oxide minerals and exploit the fine coppermineral resources are very important research tasks.In this paper, using Na2CO3and Cu（NO₃）₂·3H₂O as raw materials, the pureCu₂（OH）₂CO₃was prepared by direct precipitation method. The CuO will be obtained aftercalcining Cu₂（OH）₂CO₃in a muffle furnace at300℃for3h. The synthetic Cu₂（OH）₂CO₃andCuO were sulphidized using ethyl xanthate and butyl xanthate as sulfur source respectively.The synthetic samples before and after surface sulfidization were characterized by powderX-ray diffraction （XRD）, N2adsorption/desorption, Fourier transform infrared analysis（FT-IR）, contact angle measurement methods. The test results indicated that copper oxide andbasic cupric carbonate were surface sulfided and using xanthate as a sulfur source is a feasiblemethod. The key factors affecting the sulfidization effect were the dosage of the xanthate,besides, the carbon chain length, calcining temperature and time also play some roles. Therewere multiple valence sulfide generated on the surface of copper oxide and basic cupriccarbonate. The surface hydrophobicity, acid-base properties and the electro kinetic propertiesof sulphidized samples had been changed. We also deduced that the appropriate oxidation ofthe CuS surface contribute to improve the surface hydrophobicity.The study of the surface acid-base properties of copper oxide and basic cupric carbonatecould be able to learn the dissolution of the solid at different pH value of the solution.Moreover, the surface acid-base properties had important impact on the reactions ofadsorption, desorption, coordination as well as precipitation on the solid surface. In this paper, the acid-base properties of nano basic cupric carbonate, sulfurized basiccupric carbonate copper oxide, sulfurized copper oxide and copper sulphide were studied byautomatic potentiometric titration technology. Based on the surface complexation theory, theacid-base equilibrium constants were calculated by the computer software WinSGW usingconstant capacitance model （CCM）, the calculation result were as follows: and we simulated out the distribution of dominant components at different pH value on thesolid surface, which can provide the theoretical basis for explaining the dsorption mechanismof xanthate collector on the surface of copper oxides and carbonate.In the present research, the copper oxide minerals flotation generally use the sodiumsulfide-xanthate flotation method. At the same time, we studied the isotherm type and theeffect of pH for the adsorption of xanthate on the solid surface. The test result revealed thatthe adsorption of xanthate is fit for the BET adsorption model.According to the equilibrium concentration of xanthate at different pH value wecaculated the surface complexation constant of ethyl xanthate and butyl xanthate on the solidsurface using the computer software WinSGW. We have also deduced the ion exchangeequilibrium constant of OH-and xanthate on the solid surface. The results are as follows:...